Bloomberg/Bloomberg via Getty Images(NEW YORK) -- Google has emerged as the clear winner in the search engine race, but for the first time in more than two years Yahoo is coming out on top in terms of overall web traffic.

According to ComScore's Media Metric, which ranks the top U.S. web sites, Yahoo's web properties edged ahead of Google's in unique visitors during the month of July. Yahoo notched 196.6 million uniques, while Google trailed behind with 192.3 million.

ABC News has a content partnership with Yahoo.

The last time Yahoo led Google was in May 2011, according to ComScore. Yahoo's lead was first reported by website Marketing Land.

When reached by ABC News, Yahoo said it did not comment on third-party traffic reports. Google did not immediately respond to ABC News' request for comment.

The numbers are not based on just how many people are visiting Yahoo.com versus Google.com. Instead, ComScore rolls all of each company's sites into one bucket.

"There is a misconception in thinking Yahoo.com is overtaking Google.com," Andrew Lipsman, ComScore's vice president of industry analysis, told ABC News. "Yahoo owns a lot of different channels. Flickr, Yahoo Finance, Yahoo News and others all roll up into this number." However, Yahoo's numbers don't include Tumblr's traffic, which it acquired for $1.1 billion in May.

Lipsman said that Yahoo's surge isn't exactly a comeback. "It's not that this has come out of nowhere. This has always been there. Yahoo has usually been a close second; it wasn't so long ago that Yahoo was No. 1," he said.

Still, the jump for Yahoo represents a continuation in momentum since Marissa Mayer took over as CEO a little more than a year ago. Mayer has looked to improve key properties, including redesigns of Yahoo.com and Flickr. She has also purchased a number of start-ups.

But Google might re-emerge as the winner soon, at least when it comes to including mobile phone traffic.

"Our multi-platform numbers, which includes mobile with desktop traffic, will be released next week," Lipsman said. "I think people will be looking to see who takes the top spot there, it should provide some boost to Google."